ASTM E1641-23

Standard Test Method for Decomposition Kinetics by Thermogravimetry Using the Ozawa/Flynn/Wall Method

SIGNIFICANCE AND USE
5.1 Thermogravimetry provides a rapid method for determining the temperature-decomposition profile of a material.  
5.2 This test method can be used for estimating lifetimes of materials, using Practice E1877 provided that a relationship has been established between the thermal endurance test results and actual lifetime tests.
SCOPE
1.1 This test method describes the determination of the kinetic parameters, Arrhenius activation energy, and pre-exponential factor by thermogravimetry, based on the assumption that the decomposition obeys first-order kinetics using the Ozawa/Flynn/Wall isoconversional method (1, 2).2  
1.2 This test method is generally applicable to materials with well-defined decomposition profiles, namely, a smooth, continuous mass change with a single maximum rate.  
1.3 This test method is normally applicable to decomposition occurring in the range from 400 K to 1300 K (nominally 100 °C to 1000 °C). The temperature range may be extended depending on the instrumentation used.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Jul-2023
• ICS: 71.040.40 - Chemical analysis
• Technical Committee: E37 - Thermal Measurements
• Drafting Committee: E37.01 - Calorimetry and Mass Loss

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E1641 − 23
Standard Test Method for
Decomposition Kinetics by Thermogravimetry Using the
1
Ozawa/Flynn/Wall Method
This standard is issued under the fixed designation E1641; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* E29 Practice for Using Significant Digits in Test Data to
Determine Conformance with Specifications
1.1 This test method describes the determination of the
E473 Terminology Relating to Thermal Analysis and Rhe-
kinetic parameters, Arrhenius activation energy, and pre-
ology
exponential factor by thermogravimetry, based on the assump-
E691 Practice for Conducting an Interlaboratory Study to
tion that the decomposition obeys first-order kinetics using the
2 Determine the Precision of a Test Method
Ozawa/Flynn/Wall isoconversional method (1, 2).
E1142 Terminology Relating to Thermophysical Properties
1.2 This test method is generally applicable to materials
E1582 Test Method for Temperature Calibration of Thermo-
with well-defined decomposition profiles, namely, a smooth,
gravimetric Analyzers
continuous mass change with a single maximum rate.
E1877 Practice for Calculating Thermal Endurance of Ma-
1.3 This test method is normally applicable to decomposi- terials from Thermogravimetric Decomposition Data
E1970 Practice for Statistical Treatment of Thermoanalytical
tion occurring in the range from 400 K to 1300 K (nominally
100 °C to 1000 °C). The temperature range may be extended Data
E2040 Test Method for Mass Scale Calibration of Thermo-
depending on the instrumentation used.
gravimetric Analyzers
1.4 The values stated in SI units are to be regarded as
E3007 Practice for Selection and Use of Kinetic Reference
standard. No other units of measurement are included in this
Values in the Study of Decomposition Reactions by
standard.
Thermogravimetry
1.5 This standard does not purport to address all of the
E3142 Test Method for Thermal Lag of Thermal Analysis
safety concerns, if any, associated with its use. It is the
Apparatus
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter- 3. Terminology
mine the applicability of regulatory limitations prior to use.
3.1 Definitions—Technical terms used in this test method
1.6 This international standard was developed in accor-
are defined in Terminologies E473 and E1142 and include
dance with internationally recognized principles on standard-
activation energy, Celsius, failure, failure criterion, and ther-
ization established in the Decision on Principles for the
mogravimetric analyzer.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical 4. Summary of Test Method
Barriers to Trade (TBT) Committee.
4.1 This test method is based upon the general rate equation
that takes the form of:
2. Referenced Documents
dα ⁄ dT 5 A 1 2 α exp 2 E ⁄ RT ⁄ β (1)
3 ~ ! @ #
2.1 ASTM Standards:
where:
α = fraction reacted (dimensionless),
1
This test method is under the jurisdiction of ASTM Committee E37 on Thermal
-1
A = pre-exponential factor (min ),
Measurements and is the direct responsibility of Subcommittee E37.01 on Calo-
rimetry and Mass Loss. β = heating rate (K/min),
Current edition approved Aug. 1, 2023. Published August 2023. Originally
E = activation energy (J/mol),
approved in 1994. Last previous edition approved in 2018 as E1641 – 18. DOI:
R = gas constant (= 8.316 J/(mol K)),
10.1520/E1641-23.
T = absolute temperature (K),
2
The boldface numbers in parentheses refer to the list of references at the end of
exp = Euler’s number exponential, and
this standard.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or dα / dT = rate of change of α with T.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
4.2 Using the method of Ozawa, Flynn, and Wall (1, 2), Eq
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 1 may be solved for activation energy:
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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E1641 − 23
E 5 2 R ⁄ b ∆log β ⁄ ∆ 1 ⁄ T (2) 4.6 This iterative process is continued until the value of
~ ! @ # ~ !
activation energy no longer changes with the next iteration.
where:
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E1641 − 18 E1641 − 23
Standard Test Method for
Decomposition Kinetics by Thermogravimetry Using the
1
Ozawa/Flynn/Wall Method
This standard is issued under the fixed designation E1641; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This test method describes the determination of the kinetic parameters, Arrhenius activation energy, and pre-exponential factor
by thermogravimetry, based on the assumption that the decomposition obeys first-order kinetics using the Ozawa/Flynn/Wall
2
isoconversional method (1, 2).
1.2 This test method is generally applicable to materials with well-defined decomposition profiles, namely, a smooth, continuous
mass change with a single maximum rate.
1.3 This test method is normally applicable to decomposition occurring in the range from 400 K to 1300 K (nominally 100°C to
1000°C).100 °C to 1000 °C). The temperature range may be extended depending on the instrumentation used.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
3
2.1 ASTM Standards:
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E473 Terminology Relating to Thermal Analysis and Rheology
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E1142 Terminology Relating to Thermophysical Properties
E1582 Test Method for Temperature Calibration of Thermogravimetric Analyzers
E1877 Practice for Calculating Thermal Endurance of Materials from Thermogravimetric Decomposition Data
E1970 Practice for Statistical Treatment of Thermoanalytical Data
1
This test method is under the jurisdiction of ASTM Committee E37 on Thermal Measurements and is the direct responsibility of Subcommittee E37.01 on Calorimetry
and Mass Loss.
Current edition approved Nov. 1, 2018Aug. 1, 2023. Published November 2018August 2023. Originally approved in 1994. Last previous edition approved in 20162018
as E1641 – 16.E1641 – 18. DOI: 10.1520/E1641-18.10.1520/E1641-23.
2
The boldface numbers in parentheses refer to the list of references at the end of this standard.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E1641 − 23
E2040 Test Method for Mass Scale Calibration of Thermogravimetric Analyzers
E3007 Practice for Selection and Use of Kinetic Reference Values in the Study of Decomposition Reactions by Thermogravi-
metry
E3142 Test Method for Thermal Lag of Thermal Analysis Apparatus
4
2.2 Other Standard:
ISO 11358-2 Plastics Thermogravimetry (TG) of Polymers Part 2: Determination of Kinetic Parameters
3. Terminology
3.1 Definitions—Technical terms used in this test method are defined in Terminologies E473 and E1142 and include activation
energy, Celsius, failure, failure criterion, and thermogravimetric analyzer.
4. Summary of Test Method
4.1 This test method is based upon the general rate equation that takes the form of:
dα ⁄ dT 5 A 1 2 α exp 2 E ⁄ RT ⁄ β (1)
~ ! @ #
where:
α = fraction reacted (dimensionless),
-1
A = pre-exponential factor (min ),
β = heating rate (K/min),
E = activation energy (J/mol),
R = gas constant (= 8.316 J/(mol K)),
T = absolute temperature (K),
exp = Euler’s number exponential, and
dα
...